Development of salen metal complexes for the potential catalytic use in asymmetric reaction

摘要

This research effort is focused on the development of new transition-metal salencomplexes bearing bulky t-pentyl groups to further understand their role in the directing of substrates to the reactive metal centers. These new chiral and achiral transition-metal salen complexes also possess the ability to be novel asymmetrical catalysts. A series ofsalen ligands were prepared by the condensation of 3,5-di-t-pentyl salicylaldehyde with five different diamines: (1) 1,3-diamino-propan-2-01, (2) benzene-l,2-diamine, (3) ethylene-l,2-diamine, (4) (S,S)-1,2-diamino-l,2-diphenylethane, and (5) 1,2- diaminocyclohexane. These ligands were treated with transition metal salts to give the corresponding transition-metal salen complexes. As a result, five new systems with three crystal x-ray structures were obtained.